The present invention relates to devices for maintaining registration in a printing press.
In the past, printing presses have been known of the type having a device for printing a paper web, a device for folding the web, and a device for cutting the folded web. Although such presses have operate satisfactorily during the time that the press is under constant speed, when the speed of the press is changed, either by acceleration or deceleration of the press, the web is prone to slip in the folding device, resulting in misregistration of the web relative to the cutting device. As a result, the folded web is improperly cut at off-register locations. The inertia of idler rollers in the press and the inertia of the web mass are believed to also contribute to the misregistration during press speed changes. Hence, the web may be cut at the wrong locations during press speed changes resulting in a faulty product produced by the press.